PARENT COMPANY STATEMENTS, Condensed Statements of Condition (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Assets [Abstract]
Cash and cash equivalents	$ 205,030	$ 211,834	$ 221,038	$ 173,857
Investment in and advances to [Abstract]
Other assets	243,082	223,498
Total assets	11,410,295	10,607,295	10,746,198
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	215,221	157,459
Borrowings	77,320	97,939
Shareholders' equity	1,855,234	1,713,783	1,635,315	1,198,100
Total liabilities and shareholders' equity	11,410,295	10,607,295
Parent Company [Member]
Assets [Abstract]
Cash and cash equivalents	180,663	116,133	$ 84,460	$ 151,127
Investment securities	2,853	3,452
Investment in and advances to [Abstract]
Bank subsidiary	1,594,790	1,522,109
Non-bank subsidiaries	180,487	182,617
Other assets	12,406	8,957
Total assets	1,971,199	1,833,268
Liabilities and shareholders' equity [Abstract]
Accrued interest and other liabilities	24,850	21,546
Borrowings	91,115	97,939
Shareholders' equity	1,855,234	1,713,783
Total liabilities and shareholders' equity	$ 1,971,199	$ 1,833,268